Thermal comfort in commercial properties: what you need to know

The Significance of Thermal Comfort in Healthy Buildings

Have you ever noticed how some commercial spaces feel just right, while others are too hot or too cold? 

Achieving the perfect balance of thermal comfort is a complex science that goes beyond simply adjusting the thermostat. In this article, we will explore the fascinating world of thermal comfort and the factors that contribute to a satisfying indoor environment in commercial buildings.

What is Thermal Comfort?

According to BS EN ISO 7730, thermal comfort is a state of mind that expresses satisfaction with the thermal environment. It occurs when a person feels neither too hot nor too cold. 

To achieve thermal comfort, various factors must be taken into consideration, including ambient temperature, humidity, air circulation, personal factors like clothing and metabolic rate, and even the type of building.

In the context of commercial properties, thermal comfort plays a crucial role in maintaining a healthy and comfortable environment for occupants, ultimately impacting their productivity and overall well-being. Therefore, understanding and striving to achieve optimal thermal comfort should be a top priority for building owners and managers.

Thermal Comfort Variability in Different Spaces

Thermal comfort requirements can differ between various building types and even between different sections of a building. For instance, a hospital's operating theater, waiting room, and recovery ward have unique temperature, air circulation, and ventilation requirements. 

Office buildings may require different temperature settings for conference rooms, individual offices, and open workspace areas. 

Similarly, museums need to maintain specific climate conditions to preserve exhibits while ensuring visitor comfort. Acknowledging and addressing these diverse needs is essential for optimizing thermal comfort in commercial buildings.

How Thermal Comfort is Measured in Buildings

Understanding the importance of thermal comfort is one thing, but accurately measuring it is another challenge altogether. So, how do building professionals gauge whether the occupants are in a state of thermal comfort? Let's delve deeper into the techniques and methods used:

Objective measurements:

• Air temperature: The most straightforward metric, it's the measure of the air's temperature surrounding the occupants.
• Radiant temperature: It's the average temperature of the surroundings, including walls, windows, and other surfaces which an occupant is exposed to.
• Humidity: Indicates moisture levels which affect temperature perception.
• Air velocity: The speed of air can enhance or detract from comfort, depending on conditions.

Subjective measurements:

Questionnaires: These are often used to gather occupants' perceptions of the thermal environment. They may be asked about their comfort, whether they feel too warm or too cold, and preferences regarding the current conditions.

‍Thermal comfort indices: There are several indices, like PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied), derived from mathematical models. These models consider various parameters like air temperature, radiant temperature, humidity, air velocity, clothing insulation, and metabolic rate to estimate the overall comfort level of the occupants.‍

Use of sensors and monitoring systems: Advances in technology have made it possible to continually monitor and analyze the thermal conditions of a space. Sensors can detect even minute fluctuations in temperature, humidity, or other factors, and relay this information to building management systems. This real-time data can be invaluable for maintaining optimal conditions and quickly rectifying any discrepancies.

Standards and Regulations Governing Thermal Comfort in Buildings

The importance of thermal comfort transcends borders. Countries around the world have recognized its significance, enshrining guidelines and regulations in official standards. Let's explore the key standards related to thermal comfort in Australia, the UK, and the US:

Australia:

• AS/NZS 3666.1: Concerned with air-handling and water systems of buildings, this standard incorporates thermal comfort in relation to microbial control.
• NCC (National Construction Code): The code has requirements and recommendations related to indoor environment quality, including aspects of thermal comfort.
• AS 1668.2: This standard focuses on the ventilation design for indoor air contaminant control, indirectly affecting thermal comfort.

United Kingdom:

• BS EN ISO 7730: Widely referenced internationally, this standard offers a comprehensive guideline on the ergonomics of the thermal environment, determining the PMV and PPD indices for thermal comfort assessment.
• CIBSE Guide A: Provided by the Chartered Institution of Building Services Engineers, this guide delves into environmental design and offers insight into thermal comfort parameters and benchmarks.
• Building Regulations Part L: Addresses the conservation of fuel and power in buildings, indirectly influencing their thermal environment through regulations related to insulation, glazing, and HVAC systems.

United States:

• ASHRAE Standard 55: Developed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers, this is the predominant standard in the US for thermal environmental conditions for human occupancy. It provides guidelines for combinations of indoor thermal environmental factors and personal factors to achieve comfort.
• IECC (International Energy Conservation Code): While primarily focused on energy conservation, the code's recommendations, especially in areas like insulation and window glazing, can influence thermal comfort.

It's crucial for building professionals and owners in these regions to be familiar with these standards. Not only do they ensure the well-being and comfort of building occupants, but adherence to these standards is often legally required, ensuring structures remain compliant and avoid potential regulatory pitfalls.

The Role of HVAC Systems in Maintaining Thermal Comfort

Heating, ventilation, and air conditioning (HVAC) systems are crucial for controlling temperature, humidity, air quality, and circulation within a building. Their efficiency and performance significantly impact occupants' overall thermal comfort. 

Well-functioning HVAC systems can prevent unnecessary heating or cooling and reduce carbon emissions, contributing to a healthier environment for everyone.

Identifying and Addressing Thermal Comfort Issues

Various issues can affect thermal comfort, such as mechanical design flaws in HVAC systems, poorly programmed control logic within a building management system (BMS), or faulty sensors. Identifying and resolving these problems promptly can help building managers avoid tenant complaints and high energy bills.

Adapting to Occupants' Preferences and Changing Conditions

One of the challenges in managing thermal comfort lies in adapting to occupants' diverse preferences and changing external conditions. This could include addressing seasonal variations, fluctuations in occupancy, or even personal preferences of individual tenants. Implementing adaptable and flexible strategies for thermal comfort management can help create a more inclusive and comfortable environment for all building occupants.

The Environmental and Sustainability Impact of Thermal Comfort

Achieving optimal thermal comfort not only enhances the well-being and satisfaction of building occupants but also plays a crucial role in promoting energy efficiency and sustainability in commercial buildings. By effectively managing thermal conditions, building owners and managers can minimize energy waste and reduce their carbon footprint, contributing to a greener and more environmentally responsible property sector.

Harnessing Technology for Thermal Comfort Management

As the understanding of thermal comfort in commercial buildings continues to evolve, technology plays a crucial role in monitoring and managing indoor environments. Advanced building analytics platforms, such as PEAK, provide valuable insights into thermal comfort conditions across all zones, floors, and tenancies of a building. By leveraging such technology, building owners and managers can create healthier and more sustainable spaces that cater to the needs of occupants.

‍Discover how the PEAK platform can help you gain a deeper understanding of your building's thermal comfort and contribute to a more sustainable future. Request a callback today to learn more about our innovative solutions for commercial buildings.